* {
    margin: 0;
    padding: 0;
}

.box-page {
    width: 100%;
    height: 100%;
    /* background: royalblue; */
}

.header {
    position: sticky;
    width: 100%;
    height: 70px;
    background: sandybrown;
}

.nav-header {
    width: 70%;
    height: 100%;
    background: sienna;
    margin: 0 auto;
}